<html>
  <head>
    <title>jQuery Tutorial 1</title>
    <script type="text/javascript" src="../js/jquery.js"></script>
    <script type="text/javascript">
    function showMsg() {
        $('#btn').attr('disabled', true);
        if ($('#msg').html().length == 0) {
            $('#msg').html('<h1>Hello</h1>');
            $("#msg").css("color", "blue");
        }
        $('#msg').fadeIn();
        setTimeout(function(){
            $('#msg').fadeOut();
            $('#btn').attr('disabled', false);
        }, 3000);
    }
    </script>
  </head>
  <body>
    <div id="msg" style="display:none"></div>
    <input type="button" value="Click Me" onclick="showMsg()" id = "btn"/>
  </body>
</html>